Drainage Control Plan

This checklist provides the list of individual documents that are required for a complete application for engineering projects.

Site Development Drawings provide specific details, dimensions, and construction standards for a project that show how the property will be modified to accommodate an applicant's proposed development and comply with the County's regulations pertaining to stormwater, grading, vehicle access, roadways, and critical area regulations. Site Development Drawings for a Drainage Control Plan must be prepared by a professional engineer. See sections 3.3.2 and 3.3.3 of Volume 1 of the Pierce County Stormwater Management and Site Development Manual for more detailed information on the requirements for site development drawings.

The Drainage Report is a significant component of a Drainage Control Plan. The report contains the analysis, engineering computations, and soils report information that formulate the basis of the designs that are reflected on the Site Development Drawings. The Drainage Report includes information on existing site conditions, infiltration rates, soil types, downstream analyses, facility sizing, drainage basin mapping, and floodplain analyses. The report must be prepared by a professional engineer. See section 3.3.4 in Volume I of the Pierce County Stormwater Management and Site Development Manual for further information on Drainage Reports.

A construction SWPPP Narrative is a report prepared by a professional engineer that addresses how pollution will be controlled during construction of a project. There are thirteen elements that need to be considered and addressed. To learn more about the Construction SWPPP Narrative see sections 1.3 and 2.2.2 in Volume 2 of the Pierce County Stormwater Management and Site Development Manual.

The Maintenance and Source Control Manual is a document that is prepared by a professional engineer that explains the long term and regular maintenance requirements for a project's stormwater facilities. Source Controls are the application of pollution prevention practices on a developed site that are designed to reduce the contamination of stormwater runoff at its source. Source control measures are specific to the uses of a site. Source control measures provide guidance on how to prevent pollution from a myriad of sources such as swimming pool maintenance or above ground storage tanks. See section 3.3.6 in Volume I of the Pierce County Stormwater Management and Site Development Manual for detailed information on Maintenance and Source Control Manuals.

The Maintenance Covenant for a Drainage Control Plan is a document that is recorded on a parcel that requires a property owner to maintain the stormwater management facilities (permeable pavement, downspout infiltrations, rain gardens, bioretention, etc.) that are constructed on a site. The covenant contains maintenance instructions for each facility type. See section 3.2.9 in Volume I of the Pierce County Stormwater Management and Site Development Manual for additional information about the required Maintenance Covenant.